1. Field of the Invention
The present invention relates to a control system, and in particular to a standby battery box capable of providing electricity to a control box for driving the electric cylinder.
2. Description of Prior Art
The bottom of a sickbed used in a hospital is often mounted with an electric cylinder control apparatus. A control box in the electric cylinder control apparatus is used to drive the electric cylinder to thereby adjust the height of the sickbed and the inclination angle of a mattress. In thus way, a user can lie on the sickbed conveniently and comfortably.
The electric cylinder control apparatus provided on the sickbed has a control box, a standby battery box, and an electric cylinder. The electric cylinder is electrically connected to the control box. The standby battery box is assembled with and electrically connected to the control box. After the standby battery box is fully charged, the standby battery box can provide the electricity necessary for the operation of the control box. When the control box receives signals inputted from an external operation interface, the control box can control the action of the electric cylinder to thereby adjust the height of the sickbed or inclination angle of the mattress.
After the standby battery box of the electric cylinder is fully charged, the electric cylinder is mounted to the sickbed. When the sickbed equipped with the electric cylinder or the electric cylinder alone is delivered to the hospital and a power switch is pressed for test or use, the control box often cannot be activated to control the action of the electric cylinder. The chief reason for this phenomenon lies in that the electricity stored in a rechargeable battery of the control box has been exhausted. Since a charge-discharge device provided in the standby battery box and the components provided on a circuit board of the control box have internal resistances. Such internal resistances cause the rechargeable battery to discharge slowly and continuously. As a result, after a long period of time in storing or delivering the electric cylinder, the electricity stored in the rechargeable battery of the control box will be exhausted completely.